1. Field of the Invention
The instant invention relates generally to writing instruments and more specifically it relates to a combination ballpoint pen and mechanical pencil.
Ballpoint Pens: The ballpoint pen was invented in Hungary in 1935 by brothers Lazio and George Biro. Instead of a writing point, the ballpoint pen has a tiny metal ball in the tip of a tube filled with ink. Ink sticks to the ball and the ball rolls the ink onto the paper.
The ballpoint pen proved to be valuable to pilots, since it worked at high altitudes and did not have to be refilled frequently. In 1945 the Chicago entrepreneur Milton Reynolds introduced the ballpoint pen in the United States.
The biggest problem in the development of the ballpoint pen was creating ink of the proper consistency. If the ink was too thin, the pen leaked; if the ink was too thick, the pen clogged. Today, ballpoint pens use a heavy, oil-based ink that flows more slowly than the water-based inks generally used in fountain pens.
Mechanical and automatic pencils: In 1822 the mechanical pencil was developed. It is a device that advances the lead so that the pencil never needs sharpening. In some mechanical pencils the lead is inserted in the front end of the pencil, held in place by a slotted cylindrical clamp or an arrangement of jaws, and pushed forward by a rod or cup. A more recent development is the automatic pencil. Up to twenty pieces of lead can be inserted through the eraser end of the pencil and continuously fed to the point. Lead sizes for automatic pencils range from about 0.01 to 0.03 inch (0.03 to 0.08 centimeter).
2. Description of the Prior Art
Numerous writing instruments have been provided in prior art that are adapted to be used for forming letters, words, numbers, drawings, etc. in ink or graphite on various surfaces, such as on paper. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.